1. Field of the Invention
This invention relates to a video camera for recording a video signal, which is obtained by continuously photographing a subject, and reproducing the recording video signal in the form of still pictures or a movie; a printer apparatus which, using the video signal recorded by the video camera, produces a printed picture of the image represented by the video signal and a method of controlling the video camera and the printer apparatus. The invention further relates to a circuit which, when a print inhibit signal has been superposed upon the video signal, detects the print inhibit signal; and a method of detecting the superposed print inhibit signal.
2. Related Art
In general, a video camera performs photography at a shutter speed of 1/60 of a second. As a consequence, if it is attempted to reproduce a still picture of one frame of the moving subject from the movie video signal, only a blurred picture of the moving image can be reproduced.
In order to obtain a sharp picture when reproducing a still picture of a moving subject, photography must be performed at a high shutter speed. Although a movie video camera capable of performing continuous photography at a high shutter speed has been proposed, the impression of continuity of the image from one frame to the next at the time of movie playback is lacking and the motion of the subject in the reproduced image appears unnatural. Thus, movie playback and still playback are incompatible.
Accordingly, consideration may be given to a method through which a plurality of successive frames are photographed at a shutter speed of 1/60 of a second, and one frame among these frames is photographed at a high shutter speed (e.g., 1/250 of a second). In accordance with this method, high-speed photography is performed only once every several frames so that there is no loss in the impression of continuity of the picture.
Nevertheless, when photography is performed at a high shutter speed, the level of the video signal is lower than that of the video signal in a case where photography is performed at an ordinary shutter speed. When the resulting image is printed, therefore, the printed picture may be too dark. Furthermore, if the subject is illuminated by a fluorescent lamp, the image of the subject is affected by flickering of the fluorescent lamp.
Another problem encountered in an effort to make both still playback and movie playback feasible is how to deal with a decline in the brightness of the subject. When shutter speed is raised for the purpose of obtaining a still reproduction, there is a decline in the level of the video signal obtained from a solid-state electronic image sensing device. If there is a decline in the brightness of the subject, there is a further decline in the level of the video signal. When a video signal of a low level is reproduced in the form of a still picture, a sufficiently sharp picture is difficult to obtain.
On other hand, when a subject such as a person is photographed indoors, the subject is illuminated by the light from a lamp within the room. Since the luminance of light from a fluorescent lamp fluctuates at a frequency twice that of a commercial AC power supply, the reproduced image may develop flicker when the video signal obtained by performing photography under such illuminating light is reproduced. In other words, when a subject illuminated by a fluorescent lamp is photographed and the resulting image is played back in the form of a movie, there will be cases in which the image flickers and appears unattractive.